POS0508 PREDICTORS OF PERSISTENT DISEASE IN EARLY ARTHRITIS: 12 MONTHS RESULTS
Authors: D. Capelusnik, F. M. Dal Pra, E. E. Schneeberger, E. Soriano, J. Rosa, O. Rillo, Y. M. Ponce Delgado, A. Secco, E. Velozo, A. Berman, M. García, F. Caeiro, S. Paira, G. Citera
Journal: Annals of the Rheumatic Diseases (2022)

Background Early arthritis is an inflammatory disease with the potential to progress to persistent arthritis, such as established Rheumatoid Arthritis (RA) or other articular disease, to resolve spontaneously or remain undifferentiated for indefinite periods of time. Objectives To identify predictors of persistent RA after 12 months follow up in the Argentinean early arthritis clinic (CONAART). Methods We conducted an observational, prospective longitudinal study, including patients with early arthritis (at least 1 swollen joint with &lt;2 years of evolution) who had at least one year of follow-up. Sociodemographic and clinical data and characteristics of the disease were recorded at baseline, at 3, 6 and 12 months. After 1 year of follow-up, each patient was classified according to diagnosis: self-limited arthritis, persistent non-erosive arthritis, or persistent erosive arthritis. The association between the different predictors of diagnosis at 12 months was evaluated using multiple logistic regression, adjusted by potential confounders. Rheumatoid Factor (RF) and Anti Citrullinated Peptide Antibodies (ACPA) were included in separate models in order to avoid multicollinearity. A value of p&lt;0.05 was considered significant. Results We included 839 patients, 83% females, mean age of 57±14 years and mean disease duration of 8.2±6.2 months; 67.5% were rheumatoid factor positive and 59% ACPA positive. Disease characteristics at baseline were DAS28 5.1±1.4, swollen joints 6±5, erythrocyte sedimentation rate (ESR) 34±25 mm/h, C Reactive Protein (CRP) 4±6 and Health Assessment Questionnaire-Argentinean (HAQ-A) 1.2±0.8. After 12 months follow up, 11% of the patients were diagnosed as self-limited disease, whereas 89% were diagnosed as persistent disease. For the persistent disease, 34% presented radiograph erosions and therefore were catalogued as persistent erosive disease. The seropositivity for both, RF and ACPA, together with baseline DAS28, were the variables independently associated with the development of persistent disease at 12 months. [Model 1a: RF OR 2.33 (95% CI 1.44, 3.78) and DAS28 1.27 (1.06, 1.52); Model 2a: ACPA 2.61 (1.38, 4.93) and DAS28 1.59 (1.24, 2.04)]. (Table 1). Table 1. Predictors of Persistent Rheumatoid Arthritis at 12 months Outcomes Persistent RA Persistent RA Persistent RA Persistent RA OR (95 IC) OR (95 IC) OR (95 IC) OR (95 IC) Model 1a Model 1b Model 2a Model 2b n 708 708 507 507 Age (years ) 0.99 (0.98, 1.01 ) 0.99 (0.98, 1.01 ) 0.99 (0.97, 1.01 ) 0.99 (0.97, 1.01 ) Female gender 1.06 (0.57, 2.00 ) 1.06 (0.56, 1.99 ) 0.72 (0.30, 1.71 ) 0.72 (0.30, 1.70 ) RF positive 2.33 (1.44, 3.78 ) *** 2.45 (1.52, 3.98 ) *** - - ACPA positive - - 2.61 (1.38, 4.93 ) ** 2.63 (1.39, 4.98 ) ** DAS28 at baseline 1.27 (1.06, 1.52 ) ** 1.59 (1.24, 2.04 ) *** Categorical DAS28 MDA (vs LDA ) - 1.81 (0.85, 3.86 )^ - 2.86 (1.68, 6.99 ) * HDA (vs LDA ) - 2.83 (1.30, 6.15 )^ - 6.39 (2.42, 16.82 ) *** ^ p&lt;0.1, * p&lt;0.05, ** p&lt;0.01, *** p&lt;0.001 RF, Rheumatoid Factor; ACPA, Anti Citrullinates Protein Antigen; DAS28, Disease activity Score-28; LDA, low disease activity; MDA, moderate disease activity; HDA, high disease activity. In the patient prediction model, it can be observed that a patient with female gender, ACPA negative, and a low activity at baseline (DAS28 &lt;3.1) presents a 62.3% of likelihood of developing persistent arthritis after 12 months, while a male patient, ACPA positive, with a high baseline activity level, the probability of having persistent disease rises to 97.5%. (Figure 1) Figure 1. Matrix prediction model. Probability of diagnosis of Persistent Rheumatoid Arthritis after 12 months of follow-up. Colors represents predictive probability of achieving the outcome as follow: grey: 0-69.9%; blue: 70.0-89.9%; purple: 90.0-100%. DAS28, Disease Activity Score 28; LDA, low disease activity; MDA, Moderate Disease Activity; HDA, High Disease Activity. Conclusion Predictors of persistent arthritis after 12 months of follow up since AT diagnosis were RF and ACPA seropositivity and higher baseline disease activity level. Disclosure of Interests None declared.